1 research outputs found
Enablers and Inhibitors in Causal Justifications of Logic Programs
To appear in Theory and Practice of Logic Programming (TPLP). In this paper
we propose an extension of logic programming (LP) where each default literal
derived from the well-founded model is associated to a justification
represented as an algebraic expression. This expression contains both causal
explanations (in the form of proof graphs built with rule labels) and terms
under the scope of negation that stand for conditions that enable or disable
the application of causal rules. Using some examples, we discuss how these new
conditions, we respectively call "enablers" and "inhibitors", are intimately
related to default negation and have an essentially different nature from
regular cause-effect relations. The most important result is a formal
comparison to the recent algebraic approaches for justifications in LP:
"Why-not Provenance" (WnP) and "Causal Graphs" (CG). We show that the current
approach extends both WnP and CG justifications under the Well-Founded
Semantics and, as a byproduct, we also establish a formal relation between
these two approaches